Introduction: Why upgrade to the Sunlit B215 expansion memory?

Mar 11, 2026

Many users of Sunlit BK215 or Sunlit BK215 Plus are specifically looking for ways to expand their balcony power plant storage to improve night-time supply. The Sunlit expansion battery B215 offers exactly this possibility and increases the capacity gradually by 2.15 kWh per module.
Due to the modular design, up to three B215 modules can be connected to the head unit, enabling a total capacity of up to 8.6 kWh. This means more self-generated energy in the evening for lighting, appliances, and e-charging instead of expensive grid power.

Market trends in expanding B215 storage

The boom in balcony power plants is strongly driving demand for expansion batteries like the Sunlit B215. According to the Federal Network Agency, millions of systems are already registered, many of which are now being retrofitted with batteries.
Households with Sunlit BK215 Plus report that by expanding their B215 storage, they increase their self-consumption from under 40 percent to over 70 percent. Especially in times of high electricity prices, increasing capacity is worthwhile for anyone who generates surplus during the day.

At DRBO Greenenergy, we follow the decentralized energy transition with a focus on practical solutions for private users and specialist dealers. Our offerings include Sunlit B215 expansion batteries as well as complete kits with a pre-sale bonus, which facilitate entry and save long-term costs.

Top products: Sunlit BK215 Plus and B215 expansion battery

Product	Capacity per unit	Max. Expansion	Advantages	Reviews	Application and Feedback
Sunlit BK215 Head Unit	2.15 kWh	up to 8.6 kWh	Plug & Play, IP65, App control	4.7/5 stars	Basis for tenants, users praise simplicity
Sunlit BK215 Plus	2.15 kWh	over 8 kWh possible	Higher PV inputs, winter-ready	4.8/5 stars	Families with high loads, top flexibility
Sunlit B215 Expansion Battery	2.15 kWh	up to 3 modules	Own MPPT, stackable	4.9/5 stars	Perfect for night charging, "Game Changer"

The Sunlit B215 expansion battery is officially listed at DRBO Greenenergy and retailers such as BayWa and Globus Baumarkt. Each unit weighs approximately 31 kg and measures 47.9 x 28.9 x 30.7 cm.

Competitive comparison: B215 storage expansion

Criterion	Sunlit B215 + BK215 Plus	Deye Storage	Hoymiles Alternative
Capacity increase	up to 8.6 kWh modular	2-5 kWh fixed	1-3 kWh
PV input per module	800 W MPPT	variable	600 W
Price per kWh	affordable with pre-sale	higher	medium
Outdoor suitability	IP65, -20°C	IP65	IP54

Sunlit excels with easy retrofitting and app integration, ideal for expanding B215 storage.

Technology of the Sunlit B215 Expansion Battery

The B215 uses LFP batteries with up to 8000 cycles and a bypass function for longevity. Each unit has an MPPT input for 800 W PV power, perfect for increasing capacity.
IP65 protection and auxiliary heating make it suitable for winter. Stack up to three B215 units under the Sunlit BK215 Plus for seamless expansion.

Use cases: Night supply with B215

A couple with Sunlit BK215 Plus and one B215 covers 4.3 kWh in the evening, saving 150 euros annually at 40 cents/kWh. With two B215 modules, a family powers their washing machine and TV all night.
User feedback: "Since expanding with the B215 storage, zero grid power in the evening – fantastic!"

ROI: Increasing capacity pays off

With 500 kWh/year savings, a B215 pays for itself in 3-4 years. Pre-sale bonus reduces initial costs by up to 15 percent. Sunlit expansion storage maximizes returns.

How to upgrade your Sunlit BK215 Plus

Measure consumption: Note evening load.
Purchase B215: Check compatibility.
Stack: Fix under BK215 Plus, connect MC4.
Activate app: New module automatically recognized.

Frequently Asked Questions about Sunlit Expansion Storage

Can I connect B215 to any BK215?

Yes, up to three modules to Sunlit BK215 or BK215 Plus, max. 8.6 kWh.

Is installation easy?

Plug & Play via Schuko, no electrician needed.

How much night power does B215 storage expansion provide?

2.15 kWh per module, covers 4-6 hours of household load.

Is there a pre-sale bonus?

Yes, DRBO Greenenergy often offers discounts on B215 sets.

Future: More storage for e-car and heat pump

By 2030, the demand for modular storage will double. Sunlit B215 is compatible with smart homes and bidirectional charging.

Sources

DRBO Greenenergy product pages for Sunlit BK215 Plus and B215
BayWa Baumarkt: Sunlit Expansion Battery B215
Globus Baumarkt: Sunlit B215 Additional Storage
Digitec: Sunlit B215 Technical Data
Idealo: Sunlit B215 Price Comparison and Specs
Federal Network Agency: Balcony Power Plant Statistics

Some of the information in this article is from the internet. Product specifications may be updated at any time. For the latest information, please visit the official website or product page.